#import "AAPullToRefresh.h"
...
AAPullToRefresh *tv = [self.scrollView addPullToRefreshPosition:AAPullToRefreshPositionTop actionHandler:^(AAPullToRefresh *v){
    // do something...
    // then must call stopIndicatorAnimation method.
    [v performSelector:@selector(stopIndicatorAnimation) withObject:nil afterDelay:1.0f];
}];

tv.imageIcon = [UIImage imageNamed:@"launchpad"];
tv.borderColor = [UIColor whiteColor];
tv.borderWidth = 3.0f;
tv.threshold = 60.0f;
tv.showPullToRefresh = NO; // also remove KVO observer if set to NO.

- (void)manuallyTriggered;    // Manually trigger the block.
- (void)setSize:(CGSize)size; // Zoom in/out size.